A Dorchester man charged with fatally shooting a Cape Cod man during a home invasion last summer has been ordered held without bail. Steven Webster pleaded not guilty Wednesday to first-degree murder in the July 11 death of Andrew ­Stanley, 27, in Barnstable. Webster is also charged with home invasion, armed assault in a dwelling, armed robbery, and carrying a firearm without a license. The Cape Cod Times reported that Webster is the fourth defendant to face charges in Stanley’s death.